tonic + npm: d3

var d3 = require("d3") var NL = d3.locale ({ "decimal": ".", "thousands": ",", "grouping": [3], "currency": ["", "€"], "dateTime": "%a %b %e %X %Y", "date": "%m/%d/%Y", "time": "%H:%M:%S", "periods": ["AM", "PM"], "days": ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"], "shortDays": ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"], "months": ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"], "shortMonths": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"] }) var eur = NL.numberFormat("$,.2f"); console.log(eur(3))